Abstract / Description
Zinc oxide (ZnO) is commonly used to improve growth performance in weaned pigs, but its high-dose supplementation is increasingly restricted due to environmental concerns. Therefore, identifying effective alternatives at lower inclusion levels is of critical importance. This study evaluated activated zinc oxide (AZn) as a low-dose alternative by assessing its effects on growth performance, diarrhea incidence, nutrient digestibility, intestinal barrier function, and fecal zinc excretion in weaned pigs. A completely randomized design was used, in which 216 castrated male piglets (initial body weight 6.34 ± 0.16 kg; weaned at 21 d of age) were randomly assigned to six treatment groups, with six replicates per group and six piglets per replicate. The control group received a corn-soybean basal diet containing 100 mg/kg total Zn from feed ingredients and zinc sulfate (ZnSO₄). In the treatment groups, graded levels of AZn (125, 250, 500, or 1,500 mg/kg Zn) or a single level of conventional ZnO (1,500 mg/kg Zn) were added to the basal diet in place of the zinc sulfate in the premix. The trial lasted 28 d; on d 15, one pig per replicate closest to the pen mean was slaughtered. The results showed that compared with the control group, supplementation with AZn at any level or with 1,500 mg/kg ZnO improved growth performance and partial nutrient digestibility, and reduced diarrhea incidence (P